The Proxy Mobile IPv6 protocol provides network side-based mobility management support for a mobile node (MN), and does not require participation of the mobile node in signaling interworking related to mobility management, so that a user-side protocol stack does not need to be complexly extended. In the Proxy Mobile IPv6 protocol, a network layer is extended by adding two core functional entities, which are a local mobility anchor (LMA) and a mobile access gateway (MAG). The LMA is responsible for maintaining a reachable status of the mobile node and allocating a home network prefix of the mobile node. The MAG is located on a link to which the mobile node is anchored, and performs mobility management in place of the mobile node and completes binding registration with the LMA in place of the mobile node.
In an existing PMIPv6 mobility management solution, when the mobile node performs initial access, the mobile node first requests to be attached to a network. The MAG to which the mobile node is currently anchored acquires a mobile node identification (MN-ID) of the mobile node, and then the MAG sends the LMA a Proxy Binding Update (PBU) message that carries the MN-ID. After receiving the PBU message, the LMA returns, to the MAG, a Proxy Binding Acknowledgement (PBA) that carries a home network prefix (HNP) of the mobile node, and then the LMA negotiates with the MAG to establish a bidirectional tunnel. Subsequently, the MAG announces, to the mobile node on an access link, a router advertisement (RA) message that carries the HNP(s) of the mobile node, to complete a binding registration process.
In the existing PMIPv6 mobility management solution, because the network element devices LMA and MAG perform plenty of signaling negotiation and interworking, control functions are very complex. Especially when the mobile node moves frequently, the LMA and different MAGs need to perform more frequent and complex signaling interworking. In addition, the network element devices LMA and MAG are applicable only to the Proxy Mobile IPv6 protocol, and if the protocol is changed, the network element devices accordingly need to be changed, causing a huge waste in network construction.